Driving-rod connection for loom let-off mechanism



H. A. DAVIS 1,771,777

DRIVING ROD CONNECTION FOR LOOM LET-OFF MECHANISM July 29, 1930.

Filed Nov. 11. 1929 lnvenior.

LII l EMA n/ "H. Q L

I description and drawings and will be particu Patented July .29, 1930 UNITED STATES,

HARRY A. DAVIS, 01* norEnALn, MASSACHUSETTS, ASSIGNORIO nRAi'En commrroN, or I-IOPEDALE, MASSACHUSETTS, A oonroRArIoN or MAINE" DRIVING-ROD CONNECTION ron LOOMLET-OFF MECHANISM Application filed November 11, 1929.-. Serial No. 406,188.

This invention relates to a let-o'fl mechanism for looms and particularly to the actuating mechanism therefor. V

A let-off mechanism has for its purpose the control of the rotation of the warp beam in the loom so as to let off under even tension the warps from the beam during, and asrequired by, theweaving operation. The controlling mechanismis usually operated by connection to the lay rocker shaft so that during each cycle of movement of the lay a predetermined amount of the warps is let off.

In afamiliar type of let-off mechanism, a rocker arm is secured to the lay rocker shaft and connected by a driving rod to a pawl carrying lever which controlsthe operation of the let-off mechanism. A lost motion connection is necessary between the rocker. arm and the driving rod. The usual connection at this point consists of a stud cast on the rocker arm and a longitudinally slotted casting on the driving rod cooperating therewith. As these parts are seldom, if ever, lubricated and are not carefully finished, a great deal of wear takes place between the casting and the stud, interfering with the proper opera tion of the mechanism and necessitating fre quent replacement of the main portion of the rocker arm, of the casting on the driving rod, orboth. Y y y The object of the present invention is to provide a novel form of connection between the rocker arm and driving rod which will operate for long periods of time without sub stantial .wear, without necessity of replacement of parts, and without requiring lubrication.

The nature and objects of the invention will appear more fully from the accompanying larly pointed out in the claims.

As the invention relates to but one "feature of construction in the let-off mechanism, and as the construction and operation of the letoff mechanism itself are well "known" and familiar to those skilled in the art, it is only necessary here to illustrate and describe those parts of a familiar type oflet-ofl' mechanism with which the invention is particularly concerned inordertfully to disclose afsimple and preferred embodiment of the invention.

In the drawings: y

1 is aside elevation of a portion ofa loom with only those .parts'shownwith which the invention is particularly concerned.

Fig. 2 is an enlarged View of a portion of the construction shown in Fig. 1. v i y Fig. 3 is a righthandend elevation ofthe construction shown in Fig. 2Q Fig. 4 is a detail of the construction.

A portion of the loom side frame 1 is shown in which is mounted the usual lay rocker shaft 2 which carries the. lay swords andlay,

not shown. A portion 3 of a ratchet wheel such as employed in a familiartype of let off mechanism is illustrated and a pawl l for operating the ratchet wheel. This pawl is pivotally mounted ona pawl carrying lever 5 fulcrumed at 6. The driving rod 7 is plvoted at its rear end 8 to the pawl carryinglever 5 as usual. In the operationof the let-off mechanism, the driving rod moves endwise. lVhen it is moved to the right, viewing Fig. 1, it actuates the pawl carrying lever 5 to cause the pawl 4 to advance the ratchet wheel 3. The rearward movement of the pawl is always the same, but its return or forward movement is to an indefinite point, depending upon the amount of let-off that is to take place under the control ofthe let-ofi mechanism. It is for thisreason that there must be a lost motion connection between the rocker arm, which is for actuating the driving rod, and the driving rod.

In the construction illustrated,a two-part rocker arm is secured to thelay rocker shaft 2. The lowerpart 9 has a telescoping connection with the upper part 10 and these parts are adjust-ably secured together bythe bolt 11. The forward end of the driving rod 7 is'formed by a casting12 secured by a set screw-13 to the rod proper. This casting extends alongside the up er end of thep'art 10 of the rockerqarm and integral boss 14 extending opposite the front face of the rocker arm- The part 10-of the rocker arm isalso provided with integral sym' metrical hub portions15 onopposite sides of and at a point below its upper end. An

is provided with an ofifset link 16 having a pair of pivot studs17 and 18 connects the driving rod to the rocker arm, the stud 17 passing through a bearing in the end 12 of the driving rod, and through and concentric with the boss 14, and the pin 18 passing through a bearing in the hub and rocker arm. This link is detachably secured in place and locked in position as by meansof a washer and a cotter pin 19 passed through the pivot stud 18. The-cotterpln 19 thus serves to hold together all three parts of the device. It will thus be seen that the link not only pivotally' connects the driving rod to the rocker arm but supports the driving face of'therocker arm iscurved, as shown in Fig. 1, so as to maintain constant the disa right or left hand side of the rocker arm thus adapting thedevice to a right orleft hand loom. It will be apparent from the drawings that the device may be disassembled by removing the cotter pin 19 which per mits the three major parts of the device to be separated one from the other. The link 16 may be reinserted in the rocker arm from the opposite side while the casting 12 on the end of the driving rod when reassembled on the stud 17'of the link member will be on the opposite side'of the rocker armpf Due to the symmetrical shape of the parts the boss 14 on the casing 12 is positioned. in the proper plane to be engaged by the rockerarm.

The operation of the mechanism will be apparent. When the rocker arm swings forward, the face of its upper end engaging the face 20 of the boss 14 moves the driving rod forward in the direct-ion to actuate the let-off mechanism. During this'movement the driving rod is supported by the link and all the connections are of a pivotal character. lhere is'a minimum wear dueto thispivotal motion and to the character of theenga-gement between the rocker arm and the boss. The lost motion required when the pawl 4 retracts is readily taken care of because the boss 14 and the upper end of the rocker arm simply separate with the link 16 still supporting the driving rod.

All motion wl ich is transmitted to the driving rod from the" rocker arm is transmitted 7 through directcontact ffth'e boss letwith the arm'itself.' Since it is only'during this ing an endwise movable driving rod, a rocker arm for moving the driving rod in one direotion, a link pivoted at one end to the rocker rod.. The face 20 of the boss 14 engaging the arm and at the other end to and supporting the end of the driving rod, and a boss on the driving rod extending oppositethe rocker arm and engaged thereby when the rocker arm swings in the direction to move the driving rod.

2. In a let-off mechanism for looms, the construction'defined in claim 1, in which the boss on the driving rod is concentric with the pivotal connection of the driving rod with the link. l

3. In a let-off mechanism for looms, the construction defined in claim 1, in whichthe boss on the driving rod is concentric with the pivotal connection of the driving rod with thelink, and in which the face of the boss engaging the driving rod is curved to maintain constant the distance between the axis of said pivotal connection and the line of engagement of the boss and rocker arm as {She rocker arm rocks in engagement with the oss.

4. In a let-off mechanism for looms, the construction defined in claim 1, in which the link is provided with a pair of parallel laterally extending studs by which it is pivot ally mounted in the rocker arm and driving rod respectively, thus enabling the link to be readily. removed, together with means for locking the link in connected position.

5.. A let-01f mechanism for looms comprising an endwise movable driving rod, a rocker arm for moving the driving rod in one direction, a link pivoted at one end to the rocker arm. and at its other end .to the drivin rod to constitute a loss motion connection t erebetween, a boss on the driving rod extending opposite the rocker arm and engaged there by when the rocker'arm swings in the direc t1on to move the driving rod, said boss absorbing substantiallyall the force necessary to move the rod thereby subjecting the pivot points to no substantial force.

6. A let-01f mechanism for looms comprisng an endwise movable driving rod, a, rocker arm for moving the driving rod in one directiou, a link pivoted at one end to the rocker arm andat, its other end to the driving rod thereby to permit relative movement there; between, said link with its connection to the driving rod being capable of assembly upon the rocker arm from either side thereof, and

a boss on the driving rod extending opposite the rocker arm and engaged thereby when the rocker arm swings in the direction to move the driving rod. 2 r

7. A let-oii mechanism for looms comprising an endwise movable driving rod having a transverse bearing in its end, a rocker arm for moving the driving rod in one direction,

the said rocker arm having a transverse bearing above its rocking axis, a link having a pair 7 of laterally projecting bearing studs adapted to cooperate with the transverse bearings in the driving rod and in the rocker arm and insertable therein, and means for holding the driving rod, rocker arm and link in assembled position,

8. A let-off mechanism for looms comprising an endwise movable driving rod having a transverse bearing in its end, a rocker arm for moving the driving rod in one direction, the said rocker arm having a transverse hearing above its rocking axis, a link having a pair of laterally projecting bearing studs adapted to cooperate with the transverse bearings in the driving rod and in the rocker arm and insertable therein,-and means on one of the studs of the link for holding the dri ving rod, rocker arm and link in assembled at position.

9. A let-ofi mechanism for looms having the construction defined in claim 7, in which the link is offset between its ends and in which symmetrical bosses are disposed on the rocker arm concentric with and containing the transverse bearing aperture thus to permit the parts to be assembled with the driving rod and the link at either side of the rocker arm. 7

40 In testimony whereof, I have signed my name to this specification.

HARRY A. DAVIS. 

